Automatic furnace regulator



pril 29, 1924.

R. M. SHAFFER AUTOMATIC FQRNACE REGULATOR Filed Feb'. 2o. 1923 awo: nu!

Patented Apr.. 29, i924.

EICHLRD M. SHAFFER, 0F BALTMGRE, MARYLAND, ASSIGNOR GF lOTE-Hlijlr `'.E`

racists .TOEN W. SMITH, 0F BALTIMORE, MARYLAND.

.AUTOMATIC FUR/NACE REGULATGR. i

Application filed February 20, i923. Serial No. 620,243.

To all whom t may concer/1i.'

Be it known that E, RICHARD M. SHAFFER, a citizen of the United States, and a resident of Baltimore, in the State of Maryland, have invented certain new and useful Improvements in Automatic Furnace Regulators, of which the following is a full, clear, and exact description.

My invention relates to draftregulators for furnaces, and one of the objects of the invention is to provide a simple, inexpensive and efficient mechanism for automatically regulating the drafts and lfuel consumption in steam furnaces, hot water furnaces, hot air furnaces, steam boilers, or any other heating or power plant, either domestic or commercial.

Another object of the invention is toprovide an apparatus of this character that may be automatically operated in accordance with air pressure, steam pressure, water pressure, or by the vtemperature of air, steam or water, or by the temperature of any part of the furnacey or boiler or associ ated parts.4

Another object of the invention is to provide a positive automatic control of the ash pit damper, fire door and flue damper, whereby the automatic control is complete instead of partial, and whereby the condition of the furnace is controlled to the same extent and in the same manner as in the manual operation thereof.

A further object of the invention is to provide an apparatus of this character which may be instantly changed from automatic control to manual control, o-r vice versa.

Still another object of the invention is to provide a time-controlled mechanism by means of which the apparatus may be thrown into automatic operation at any desired time.l y

Another object of the invention is to provide a device of this nature which is extremely simple in construction and inexpensive in manufacture, and which may be quickly and easily applied to any type of furnace.

Numerous other advantages will be appar- ;ent to those skilled in the art to which the invention appertains from the following detailed description when taken in connection with the accompanying drawings, in which:

plete apparatus, the mechanism being shown as under automatic control.

Figure 2 is a'vertical sectional view of the lire door supporting means.

Figure is a. detail sectional view of a supplementary means for supporting and vertically adjusting the fire door.

Figure e' is a bottom plan view of a releasing mechanism; and

Figure is a. detail perspective view of a bracket, showingin outline a bell crank lever mounted thereon.

liigure 6 is a fragmentary plan View ofthe mechanism associated with the fire door; the link la being in section. y

feferringto the drawings more in detail, numeral l refers to any ordinary type of furnace which is pro-vided with Vthe conventional ash pit damper 2, fire door 3, and flue damper 4.

For purposes of illustration only I have shown inounted'on the top of the furnace the ordinary pressure operated diaphragm 5, but it will be understood that in place of this diaphragm l may substitute any other form of pressure or heat-controlled apparatus, as hereinbefore mentioned. A frame 6 is pivotally mounted adjacent to pressure diaphragm, and this frame carries a bracket 7 in which is mounted an arm 8; the arm being held in adjusted position in the bracket by means of the set-screw 9 or the equivalent. rThe frame 6 carrying the arm 8 is moved about its pivot in the usual inannervby connection with the pressure diaphragm. The arm 8 is also provided with the ordinary adjust-able counterbalance weight lO.

A chain ll, or equivalent connecting means, is attachedatone end to the flue damper, andV its otherend is attached to the rear end of the arm 8. Of course, the

i chain may be attached to the arm yin any desired manner,r but l prefer to provide the arm with a hook 12 for receiving a link of the chain, clearly illustrated inv the drawings.

Pivotally attached to the forward end of the arm 8, as by means of a hook 13, is a downwardly extending link le, which link is pivotally attached at its lower end to the horizontal arm 15 of a bell crank lever mounted on the Vfurnace front adjacent to the fire door. Any preferred means may be Figure l is a front elevation of the com employed for pivotally connecting the link and be-ll crank, but l have shown hereinV a hook 16 carried by the lower'end of the link and adapted to engage an eye 1n the vbell cranklever.

A' bracket 17 Yis mountedonthe redoor, and this bracket is provided'with an eye which is adapted to be engaged byV the hook 18; the hook being pivotally connected at its Opposite endto the verticaly arm 19r of thebellcrank lever. The bell crank lever is preferably aligned with the bracket 17 by mountingfit on*l a .bracket B4, as clearly shown in Fig.y 5i

The link 14 is also providedvvith a plurality of hook members 20, and a chain 21 is adapted to engage over one of these hooks, While the 'opposite end of the chain` is'connected with thefash pit damper 2.

The operation of the apparatus thus far desc-ribedis' as followsz" v Assume the various parts to be in the position shown in they drawings; then upon a Vrise in temperature or increase in pressure the thermostatic element or the diaphragm, whichever isemployed, will act to cause the arm 8 to move about its pivot, the rear end off the arm being raised and the yforward end being lowered. It is obvious that as the rear end of the arm 8 is raised the flue damper will be opened, the amount of opening depending, of course, on the extent of movement of the arm 8; and it will also be apparent that as the front end of the arm 8 is lowered the link 14 will cause the bell 'crank yto rotate about its pivot, and the hook connection between the vertical arm of the bell crank lever and the bracket 17 will cause the fire door to swing to open position, the extent to.: which the door is opened depending, of course, on the extent ofmovement of the arm 8; When 'the for'- ward end of the arm 8 and the link 14 move downwardly, it will also be noted that the chain connection 21 between the linkV and the ash pit damper permits the latter'to move by gravity toward closed position,V

The extreme simplicity of the construction, and the eEectiveness of the invention,

if as so far described, will be obvious. As the arm moves in one direction the flue damper is opened, the ash pit damper is closed, and the fire door is opened, thereby checking the lire in eXactlythe same manner that is em ployed in the manual control of a furnace; and as the arm ismoved in the opposite direction the flue damper `is closed, the ash pit damper is opened, and the fire door is closed, thereby creating a'favorable draft for increasing the intensity ofthe fire.

It will be understood, of course,.thatthe various parts will be operated automatically at such times as may be necessaryin order to maintain a. uniform pressureor tempera;

ture, and' that the movements. willbe effected through the VYoperation of" the Vthermostat' or diaphragm, `as previously described. For

purposes of illustration only l have shown employed herein a pressure-Operated diaphragm', and the apparatus is set Vfor'the desired pressure bythe adjustment of the counterbalance weight 10 along the arm 8 -initheusual'man'nerg but it is t o be noted that the sensitiveness of the device may be variedjinmy construction by moving the arm 8 bodily and securing it in adjusted position by means of the set-screw 9.

Y Itv is Valso, to be noted here that the'ire door may be instantly released from or 'connected withv the automatic control'by merely disconnecting or connecting the yhook 18 with the" bracket 17. Also the ash pit damper 2 ymay be rendered inoperative by removing the chain 21 from the upper hook 20 and placingit on the lower hook 20; and the flue `damper 4 isy renderedinoperative by removing the chain 11 from the hook l2.

It is highly desirable, ofcourse, to-bank the fires and check the draft during the night, and to provide some means whereby during'the early morninghours the position of the damper will'be automatically changed to create a favorable draft and thus buildk upthe fire, and'I will now describeV a most simple arrangement by which this is accomplished.

Mounted on the beams, or the like, in the cellar is aplate 22 provided with a suitable slot 23. VPivotally attached to the forward portionV of the arm 8 is an upwardly eX- tending rod 24 provided with a notch tor engaging an'edge of the slot 23. To set the furnace for the night it is only necessary to move the arm 8 and rod 24 downwardly untilthe notch becomes aligned with the'edge of the slot, and then moving the rod over so that the notch will engage the edge, thereby Asecuring thejparts in position to check the fire during the night. Vhen so positioned the ash pit damper is closed, the flue damper is open, and the fire door is` open. The various elements will remain in this position until the rod 24 is released, whereupon the counterbalance weight 10 will causethe positionof the partsf'to bel reersedto create a draft and to build up the re. Y

For the purpose of releasing the rod k24 l have provided a trigger 25 which isfpivotally mounted on the plate 22 adjacent tothe rod Vtrigger is so arranged that it may be reversedA to suit different installations; the reversed position beingin'dicated in broken lines. y The trigger 425A `may be moved by any prellO ferred form of timing mechanism, butY l have illustrated herein a conventional alarm clock 26 provided with any ordinary arm 27 for winding the same. A. chain 28 is attached to Lthe winding arm 27 and extends upwardly over a pulley 29 and thence over to the trigger 25to which it is attached. An abutment 30 is provided to limit the unwinding movement of the arm 27.

The operation of this simple construction will be obvious from the foregoing description. The alarm is set for a certain hour and the winding arm 27 is rotated through approximately a half a turn, so that it would be in a position opposite to that shown in the drawings. At the hour set the alarm mechanism will be released and the arm 27 will begin to move downwardly, thereby eX- erting a pull on the chain 28 and drawing the trigger over to trip the rod 2li. The purpose of the abutment 30 lis merely to limit the extent of movement of the winding arm, thereby avoiding the necessity of fully winding the alarm each time the apparatus is set.

lt should be mentioned here that at times it may vnot be desired to check the fire to the full extent during the night, and in such cases it is only necessary to remove the hook 18 from engagement with the fire door, thereby permitting the latter to be closed for the night.

In the ordinary construction of furnaces the doors are loosely mounted on the hinges, so that they may be raised to free the latch and then be swung to open position; and it will be understood that in the present invention the movement of the fire door is automatically controlled, and hence some means* must be provided for freeing the latch in order that the fire door may be opened. For this purpose l have provided a set-screw 3l which is adapted to engage the lower pintle 32 of the fire door, thereby moving the door' upwardly the desired extent to free the latch. In some installations the lire door may be so loosely mounted that the set-screw is not adequate for the purpose, and in such instances I employ a plate 33 which is apertured to receive the upper pint-le. In the use of this plate it is moved to the right (Fig. 3) until the door has been lifted slightly, and the end of the plate is then turned at an angle, as indicated in Fig. 3, thereby securing the door in its adjusted position; the set-screw 3l then being operated to lift the door the remaining distance required to free the latch.

Whenever the lire door is released from automatic or time control, and it is to be locked in closed position, it is apparent that it is only necessary to rotate the set-screw, ilheriby lowering the door and engaging the atc lirom the foregoing description it will be apparent that l have devised an apparatus which is most simple in construction and inexpensive in manufacture, and one which may be quickly and easily applied to a furnace; that, in accordance with my invention, the 'flue damper, ash pit damper and fire door will be automatically controlled in accordance with the desired conditions in the furnace or boiler, and that this automatic control of the drafts is accomplished in exactly the same manner as is employed in the manual operation of a furnace; that the apparatus may be instantly changed from automatic rcontrol to manual control;

and that, in accordance with the timing feature of ythe invention, the tire may be checked for the night, and at any hour desired the apparatus will be thrown into automatic operation, whereupon the dampers, etc., will move to a position to create a favorable draft for buildingl up the tire.

in accordance with the patent statutes, l have described what l now believe to be the best embodiment of the invention` but .l do not wish to be understood thereby as limiting myself or the scope of the invention, as many changes and modifications may be made without departing from the spirit of the invention; all such l aim to include in the scope of the appended claims.

W hat I claim as new and desire to secure by Letters Patent is:

' l. in a furnace, a pivoted arm, an automatic control for moving' said arm, flexible connections between the arm and the flue damper and ash pit damper, whereby the flue damper and ash pit damper are positively opened and gravity closed, and a positive link connection between said armV and the iire door kfor opening and closing said door.

2. In a furnace, a Ere door, a bell-crank lever adjacent tov the fire door, a link pivotally attached to one arm of the bell-crank lever, said link adapted to engage the firel door, a second link pivotally attached to the to the second mentioned link and having its other end connected with the ash-pit damper, a pivoted arm connected to the second-mentioned link, and an automatic control for moving the arm.

3. lin a furnace, a lire door, a bell-crank lever adjacent to the iredoor, a link pivotally attached to one arm of the bell-crank lever, said link adapted to engage the lire door, a second link pivotally attached to the other arm of the bell-crank lever, a flexible member having one end attached to the second-mentioned link and having its other end connected with the ash-pit damper, a pivoted arm connected to the second-mentioned link, an automatic control for moving the arm, a rod extending upwardly from said arm, Va trigger for engaging the rod in one position thereof, and ltime controlled vmeans for releasii'ig the trigger.YK

4, ln a furnace, a tire door,'abellcrank lever adjacent to the fire door, a lug mount-V ed on the fire door and extending outwardly beyond the plane of the door hinges, a link pivotally attached t0 one arm of the bell* crank lever, the other end of said link adapted to detachably engage said lug, a second link -pivotallycattached to the other arm of the bell-crank lever, a flexible member having one end attached to the second-mentioned link and having its'other end con-V door, and a flexible connection between said link and the ash pit damper. Y

A. 6. In a furnace, a horizontally swinging re door, said door being loosely mounted, a set-screw adapted to engage the lower pintle of the door whereby the door may be raised to free its latch,'a bell crank lever adjacent the door, connecting means between the door and one arm of the bell crank lever, a link connected to the other arm of the bell crank lever, and means for moving said link in accordance with furnace conditions.

7.1ln a furnace, a horizontally swinging fire door, said door being loosely mounted, a plate'associated with the upper pintle of the door for taking up a portion of the loose connection, a set-screw adapted to engage the lower pintle of the door whereby the means between the door and one arm of the v bell crank lever, a link connected yto theV other arm of the bell crank ,-lever, and means for moving said arm in accordance with boiler conditions. y

8. In a' furnace, a pivoted arm, an automatic control for Vmoving the arm,',connec tions between thea-rm and the flue damper, ash pit damper and lire door, a rod pivotally attached to the arm, a slotted plate, said rod received inthe slot ofthe plate,vsaid rod provided with a Ynotch adapted to engage an edge of the slot to hold the armin non-automatic control position, and a trigger for releasing the rod to permit the arm Yto return to automatic control position.

'9. In a furnace, a pivoted arm, an automatic control for said arm, connections between said arm and the furnace dampers, a rodpcarried by the arm, a plate adjacent said rod, the rod being provided with a notch adapted to engage the plate to hold the arm in non-automatic control position, ya trigger pivotally mounted adjacent to the'rod, a timing mechanism, a flexible connection between lthe timing mechanism and the trigger, whereby the latter may be moved-to vrelease the rod to permitthe arm' to return to Y,

automatic control position. Y

10. In a furnace, va horizontally swinging lire door, said door being looselyV mounted, a plate associated with the upper pintle of the door for takinof un the loose connection whereby the door is raised to free it from its latch, a ybell-crank lever adjacent the door, connecting means between the door and one yarm 4of the bell-crank lever, a link connected to the other arm of the bell-crank lever, and meansfor moving said arm in accor-dance with boiler conditions. v

RICHARD M. SHAFFER-- 

